Wireless communications networks are widely deployed to provide various communication services such as voice, video, packet data, messaging, broadcast, and the like. These wireless networks may be multiple-access networks capable of supporting multiple users by sharing the available network resources.
A wireless communications network may include a number of access points. The access points of a cellular network may include a number of base stations, such as NodeBs (NBs) or evolved NodeBs (eNBs). The access points of a wireless local area network (WLAN) may include a number of WLAN access points, such as Wi-Fi nodes. Each access point may support communication for a number of user equipments (UEs) and may often communicate with multiple UEs at the same time. Similarly, each UE may communicate with a number of access points, and may sometimes communicate with multiple access points and/or access points employing different access technologies. An access point may communicate with a UE via downlink and uplink. The downlink (or forward link) refers to the communication link from the access point to the UE, and the uplink (or reverse link) refers to the communication link from the UE to the access point.
As cellular networks become more heavily utilized, operators are seeking ways to increase capacity. One approach may include the use of WLANs to offload some of the traffic and/or signaling of a cellular network. WLANs (such as Wi-Fi networks) may offer attractive features because, unlike cellular networks that operate in a licensed spectrum, Wi-Fi networks may operate in an unlicensed radio frequency spectrum band, and are thus available for use by various entities subject to established rules for providing fair access to the spectrum. In some deployments, various operators may wish to access the unlicensed radio frequency spectrum band using one or more nodes that operate synchronously to access the unlicensed radio frequency spectrum band. However, if different deployments of synchronous nodes of different operators do not have time-aligned periods for channel contention, one or more operators may not be able to access unlicensed radio frequency spectrum band for a relatively long period of time. Thus, while nodes within an operator deployment may operate synchronously, the nodes of one operator may be asynchronous relative to nodes of other operator deployments. Thus, operators may need to employ techniques to ensure that nodes of the same or different operator deployments, using the same or different techniques for accessing the unlicensed radio frequency spectrum band, can fairly and effectively use the unlicensed radio frequency spectrum band, while also complying with established rules for spectrum access.